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Finding the Fourth Proportional to 28.18, 42.17 and 21.38

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Solution

The fourth proportional to 28.18, 42.17 and 21.38 is: 32.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.18 : 42.17 = 21.38 : x
  2. Step 2: Convert to fraction form
    28.18/42.17 = 21.38/x
  3. Step 3: Cross multiply
    28.18x = 42.17 × 21.38
  4. Step 4: Simplify right side
    28.18x = 901.49
  5. Step 5: Solve for x
    x = 901.49/28.18
  6. Step 6: Final answer
    x = 32.00

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.